/Engine/Source/Runtime/PreLoadScreen/Public/PreLoadScreen.h
IMPORTANT: This changes a LOT of functionality and implementation details. EarlyStartupScreens happen before the engine is fully initialized and block engine initialization before they finish. this means they have to forgo even the most basic of engine features likeUObjectsupport, as they are displayed before those systems are initialized.
EPreLoadScreenTypes GetPreLoadScreenType() const